Dysphagia and Muscle Weakness Caused by Botulinum Toxin Poisoning after Cosmetic Injection: Three Case Reports and Clinical Warnings.

Botulinum toxin (BoNT), a neurotoxic protein produced by Clostridium botulinum, is widely used for cosmetic and therapeutic purposes, including managing muscle hyperactivity, movement disorders, and chronic migraines by blocking acetylcholine release at neuromuscular junctions. While generally safe, it can cause localized adverse effects (erythema, ptosis, pain) and rare systemic complications (dysphagia, dysarthria, respiratory distress), particularly with improper dosing. From August 2024, This case report presents three female patients, aged 25, 50, and 49, in the Affiliated Hospital of Yunnan University, who experienced severe complications following the injection of botulinum toxin. The first patient, developed dysarthria and dysphagia 18 days post-injection, with a history of administration in northern Myanmar. The second patient, reported similar symptoms 3 days after a lesser dosage was injected into her masseter muscles. The third patient, exhibited fatigue and difficulty in eye opening and swallowing 7 days after receiving botulinum toxin. The symptoms of all patients were significantly improved after receiving symptomatic treatment in our hospital. The three cases presented are significant as they highlight the potential complications arising from botulinum toxin injections, particularly when used for cosmetic purposes. Botulinum toxin, though effective for cosmetic and therapeutic applications, carries risks of localized (muscle weakness, ptosis, bone loss) and systemic complications (generalized weakness, botulism), particularly near critical anatomical structures. Dysphagia and dysarthria, observed in cases post-injection, likely arise from toxin diffusion causing unintended muscle impairment. Treatment outcomes vary, with supportive care or invasive interventions often yielding limited improvement, highlighting management challenges. Clinicians must prioritize patient education, informed consent, and vigilant post-treatment monitoring for neurological symptoms. Future guidelines should standardize safe administration practices-optimizing dosage, injection sites, and follow-up-while enhanced practitioner training and multidisciplinary approaches are critical to mitigating risks and improving outcomes. This underscores the imperative for heightened clinical awareness and robust safety protocols to safeguard patient welfare.